Giardia cysts and Cryptosporidium oocysts are protozoan intestinal parasites. As used herein "Giardia" refers to a genus of flagellates that parasitize the small intestine of mammals. One species of Giardia of particular significance, G. Lamblia, has eight flagella and a flattened heart-shaped appearance under microscope. The organism attaches itself to the intestinal mucosa by sucking organs.
As used herein, "Cryptosporidium" refers to a genus of coccidian sporozoan, which are opportunistic parasites in mammals. Cryptosporidiosis, in immunocompetent individuals, is self-limiting. In compromised individuals, it may be fatal.
Outbreaks of giardiosis and Cryptosporidiosis are typically caused by contamination of water supplies. These water borne organisms are difficult to detect. Presently, seven Giardia cysts per 100 L of water is considered potable. To evaluate water supplies one must be able to reliably and reproducibly detect such a level of Giardia, at a reasonable cost.
Although no acceptable level has been defined for Cryptosporidium, such definition is expected in the near future. The level of Cryptosporidium oocysts in water supplies, like Giardia, will be a small, limited number.
Present technology does not presently permit the detection of Giardia cysts or Cryptosporidium oocysts from water supplies in a reliable, reproducible manner at a reasonable cost. Giardia and Cryptosporidium are presently detected using cartridge filters for concentrating organisms from large volumes of water, followed by immunofluorescence assay (IFA). This method is time consuming, labor intensive and requires considerable analytical expertise. The method suffers from a low efficiency in recovering cysts and oocysts from the sample and frequently produces questionable results.
The present invention is directed to methods and articles of manufacture for the detection of Giardia cysts and Cryptosporidium oocysts. The methods are less time consuming, less labor intensive and are more reliable in the recovery of Giardia cysts and Cryptosporidium oocysts than previous methods.